This invention relates to a chemically bonded phosphate corrosion protection material and process for application of the corrosion protection material for corrosion prevention.
There have been developed multifarious paints and paint-like coatings of a large variety of formulations for preventing corrosion of exposed iron or steel structures and surfaces. For example, polymer paints, in particular, provide corrosion protection; however, these coatings often can peel or flake off of metal surfaces, particularly in adverse conditions.
Another approach has involved cladding or brazing an alloy onto the surface of steel or other metal to be protected from corrosion. However, these modifications can be very expensive. This approach necessitates a clean, rust-free surface to which the cladding or brazed alloy will adhere. The material used for cladding or brazing must have a coefficient of thermal expansion similar to that of the material to be protected to prevent delamination or cracking of the coating during thermal cycling. It is also difficult to apply a brazed-on coating to both the inside and outside of a pipe at the same time.
More recently, where safety or environmental considerations have been of paramount importance, corrosion-resistant stainless steels or xe2x80x9csuper alloysxe2x80x9d have been used in applications where prevention of corrosion of steel structures or pipes was absolutely essential. These materials are expensive and more difficult to produce than conventional steel materials.
Therefore there is still a need for economical, efficient corrosion protection methods and materials which can be easily applied and which will reliably adhere to the surface being treated in chemically adverse or saline environments.
It is an object of this invention to provide an efficient corrosion protection method and durable corrosion protection material.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. The claims appended hereto are intended to cover all changes and modifications within the spirit and scope thereof.
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, there has been invented a chemically bondable phosphate corrosion protection material and process for application of the corrosion protection material for corrosion prevention. A slurry of iron oxide and phosphoric acid is used to contact a warm surface of the iron, steel or other metal to be treated. In the presence of ferrous ions from the steel or other metal, the slurry reacts to form iron phosphates as reaction products which chemically bond onto the surface of the steel.